param.c contains default values for a number of parameters that are used to tune system performance. Parameters that you can modify are listed below. As some parameters can be changed also in the configuration file check parameter consistency before rebuilding the kernel.
| Tunable param.c File Entries | ||
| Parameter | Default Value | Configuration File val |
autonice |
0 | Set to 1 if AUTONICE defined |
bufcache |
3 | bufcache |
bufhsz |
512 | None |
hz |
100 CLOCKS_PER_SEC |
<machine/ machtime.h>
|
create_fastlinks |
1 | None |
inohsz |
512 | None |
maxuprc |
64 | maxuprc |
maxuthreads |
256 | maxuthreads |
maxusers |
system dependent | maxusers |
ncallout |
36+8*maxuser+threadmax |
maxcallouts |
nchsize |
NVNODE*11/10 |
None |
nchsz |
128 | None |
| 120 if clist ptys | ||
nclist |
(pseudo-device pty #) are |
nclist |
| configured, the default | ||
value is 60+12*maxusers |
||
ndquot |
NVNODE+(MAXUSERS * NMOUNT/4 |
None |
nmount_max |
256 | None |
nquota |
(MAXUSERS*9)/7+3 |
None |
nvnode |
NPROC+(2*MAXUSERS)+128 |
None |
open_max_hard |
4096 | None |
open_max_soft |
4096 | None |
path_num_max |
64 | None |
port_hash_max_num |
50*(6*threadmax+2000)
|
Based on threadmax |
port_max_num |
6*threadmax+2000 |
Based on threadmax |
port_reserved_max_num |
6*threadmax+2000
|
Based on threadmax |
set_max_num |
2*threadmax+200 |
Based on threadmax |
select_max_elements |
1024+NPROC*4 |
None |
select_chunk_elements |
256 | None |
spechsz |
64 | None |
sys_v_mode |
0 | sys_v_mode |
task_max |
1+(20+(8*maxusers)) |
task_max |
threadmax |
8192 | threadmax |
ucred_max |
128 | None |
ubc_minpercent |
10 | ubcminpercent |
ubc_maxpercent |
100 | ubcmaxpercent |
ufs_blkpref_lookbehind |
8 | None |
vm_max_wrpgio_kluster |
32*1024 | writeio_kluster |
vm_max_rdpgio_kluster |
16*1024 | readio_kluster |